Murray Rothbard

The fact that natural-law theorists derive from the very nature of man a fixed structure of law independent of time and place, or of habit or authority or group norms, makes that law a mighty force for radical change.

Many of Judy Blume's books - which I devoured when I was growing up and where I found characters that were believable because they were a lot like me - caused considerable consternation when they were first published, but now they're widely accepted as an essential part of the children's literary canon.